Method and system for wireless communication

ABSTRACT

Certain aspects of a method and system for wireless communication are disclosed. Aspects of one method may include a receiver that handles wireless communication. The receiver may be enabled to dynamically vary spacing between two or more pilots and/or the size of one or more pilots within at least one frame based on a determined symbol rate.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This application is a continuation of U.S. patent application Ser. No.13/483,148, entitled “METHOD AND SYSTEM FOR SATELLITE COMMUNICATION,”filed on May 30, 2012, which is a continuation of U.S. patentapplication Ser. No. 11/692,702, entitled “METHOD AND SYSTEM FORSATELLITE COMMUNICATION,” filed on Mar. 28, 2007, which makes referenceto, claims priority to, and claims the benefit of U.S. ProvisionalApplication Ser. No. 60/831,888 filed on Jul. 19, 2006.

This application makes reference to:

-   U.S. patent application Ser. No. 11/385,390, filed on Mar. 21, 2006;    and-   U.S. patent application Ser. No. 11/385,081, filed on Mar. 21, 2006.

Each of the above referenced applications is hereby incorporated hereinby reference in its entirety.

FIELD OF THE INVENTION

Certain embodiments of the invention relate to communication systems.More specifically, certain embodiments of the invention relate to amethod and system for satellite communication.

BACKGROUND OF THE INVENTION

Broadcasting and telecommunications have historically occupied separatefields. In the past, broadcasting was largely an “over-the-air” mediumwhile wired media carried telecommunications. That distinction may nolonger apply as both broadcasting and telecommunications may bedelivered over either wired or wireless media. Present development mayadapt broadcasting to mobility services. One limitation has been thatbroadcasting may often require high bit rate data transmission at rateshigher than could be supported by existing mobile communicationsnetworks.

Terrestrial television and radio broadcast networks have made use ofhigh power transmitters covering broad service areas, which enableone-way distribution of content to user equipment such as televisionsand radios. By contrast, wireless telecommunications networks have madeuse of low power transmitters, which have covered relatively small areasknown as “cells”. Unlike broadcast networks, wireless networks may beadapted to provide two-way interactive services between users of userequipment such as telephones and computer equipment.

Standards for digital television terrestrial broadcasting (DTTB) haveevolved around the world with different systems being adopted indifferent regions. The three leading DTTB systems are, the advancedstandards technical committee (ATSC) system, the digital video broadcastterrestrial (DVB-T) system, and the integrated service digitalbroadcasting terrestrial (ISDB-T) system. The ATSC system has largelybeen adopted in North America, South America, Taiwan, and South Korea.This system adapts trellis coding and 8-level vestigial sideband (8-VSB)modulation. The DVB-T system has largely been adopted in Europe, theMiddle East, Australia, as well as parts of Africa and parts of Asia.The DVB-T system adapts coded orthogonal frequency division multiplexing(COFDM). The ISDB-T system has been adopted in Japan and adaptsbandwidth segmented transmission orthogonal frequency divisionmultiplexing (BST-OFDM).

While 3G systems are evolving to provide integrated voice, multimedia,and data services to mobile user equipment, there may be compellingreasons for adapting DTTB systems for this purpose. One of the morenotable reasons may be the high data rates that may be supported in DTTBsystems. For example, DVB-T may support data rates of 15 Mbits/s in an 8MHz channel in a wide area single frequency network (SFN). There arealso significant challenges in deploying broadcast services to mobileuser equipment. Because of form factor constraints, many handheldportable devices, for example, may require that PCB area be minimizedand that services consume minimum power to extend battery life to alevel that may be acceptable to users. Another consideration is theDoppler effect in moving user equipment, which may cause inter-symbolinterference in received signals. Among the three major DTTB systems,ISDB-T was originally designed to support broadcast services to mobileuser equipment. While DVB-T may not have been originally designed tosupport mobility broadcast services, a number of adaptations have beenmade to provide support for mobile broadcast capability. The adaptationof DVB-T to mobile broadcasting is commonly known as DVB handheld(DVB-H). The broadcasting frequencies for Europe are in UHF (bands IV/V)and in the US, the 1670-1675 MHz band that has been allocated for DVB-Hoperation. Additional spectrum is expected to be allocated in the L-bandworld-wide.

The DVB-S2 is a second generation standard for satellite broadbandapplications, developed by the digital video broadcasting (DVB) project.The DVB-S2 standard may be enabled to support quadrature phase shiftkeying (QPSK), 8PSK, 16 phase asymmetric phase shift keying (16APSK),and 32APSK modulation systems. The DVB-S2 standard may be enabled totransport single or multiple streams in a variety of formats, forexample, MPEG-2 transport streams and each stream may be protected in adifferent manner.

Communication systems may employ coding to ensure reliable communicationacross noisy communication channels. These communication channels mayexhibit a fixed capacity that may be expressed in terms of bits persymbol at a certain signal to noise ratio (SNR), defining a theoreticalupper limit known as the Shannon limit. As a result, coding design hasaimed to achieve rates approaching this Shannon limit. One such class ofcodes that approach the Shannon limit is low density parity check (LDPC)codes.

The LDPC encoding technique may be highly complex and its generatormatrix may require storing a very large, non-sparse matrix. From animplementation perspective, a key challenge in LDPC code implementationmay include achieving a connection network between several processingnodes in a decoder. Further, the computational load in the decodingprocess, specifically the check node operations may pose problems orchallenges such as performance, complexity and storage requirements.

Further limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of skill in the art, throughcomparison of such systems with some aspects of the present invention asset forth in the remainder of the present application with reference tothe drawings.

BRIEF SUMMARY OF THE INVENTION

A method and/or system for satellite communication, substantially asshown in and/or described in connection with at least one of thefigures, as set forth more completely in the claims.

These and other advantages, aspects and novel features of the presentinvention, as well as details of an illustrated embodiment thereof, willbe more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a block diagram illustrating an exemplary mobile terminal, inaccordance with an embodiment of the invention.

FIG. 1B is a block diagram illustrating exemplary communication betweena dual-band RF receiver and a digital baseband processor in a mobileterminal, in accordance with an embodiment of the invention.

FIG. 1C is a block diagram of an exemplary satellite receiver, inaccordance with an embodiment of the invention.

FIG. 2A is a diagram that illustrates an exemplary QPSK modulated framestructure without a pilot that may be utilized in connection with anembodiment of the invention.

FIG. 2B is a diagram that illustrates an exemplary 8PSK modulated framestructure without a pilot that may be utilized in connection with anembodiment of the invention.

FIG. 3A is a diagram that illustrates an exemplary QPSK modulated framestructure with pilots that may be utilized in connection with anembodiment of the invention.

FIG. 3B is a diagram that illustrates an exemplary 8PSK modulated framestructure with pilots that may be utilized in connection with anembodiment of the invention.

FIG. 4A is a diagram that illustrates an exemplary 8PSK modulated framestructure with pilots that may be utilized in connection with anembodiment of the invention.

FIG. 4B is a diagram that illustrates an exemplary 8PSK modulated framestructure with variable pilots, in accordance with an embodiment of theinvention.

FIG. 5 is a diagram that illustrates an exemplary frame structure forsupporting mobile satellite video reception, in accordance with anembodiment of the invention.

FIG. 6 is a flowchart illustrating exemplary steps for satellitecommunication, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention may be found in a method and systemfor satellite communication. Aspects of the method and system maycomprise a receiver handling digital video broadcasting. The receivermay be enabled to dynamically vary spacing between one or more pilotswithin at least one frame based on a determined symbol rate. The size ofeach of a plurality of received programs may be determined and thespacing between one or more pilots may be dynamically varied based onthe determined size of each of the plurality of received programs.

FIG. 1A is a block diagram illustrating an exemplary mobile terminal, inaccordance with an embodiment of the invention. Referring to FIG. 1A,there is shown a mobile terminal 150 that may comprise a RF receiver 153a, a RF transmitter 153 b, a digital baseband processor 159, a processor155, and a memory 157. A receive antenna 151 a may be communicativelycoupled to the RF receiver 153 a. A transmit antenna 151 b may becommunicatively coupled to the RF transmitter 153 b. U.S. applicationSer. No. 11/385,390 filed on Mar. 21, 2006, provides a detaileddescription of a cellular network and/or digital video broadcast networkin which a mobile terminal may communicate, and is hereby incorporatedby reference in its entirety. For example, the mobile terminal 150 maycommunicate in the video broadcast network.

The RF receiver 153 a may comprise suitable logic, circuitry, and/orcode that may enable processing of received RF signals. The RF receiver153 a may enable receiving RF signals in a plurality of frequency bands.For example, the RF receiver 153 a may enable receiving DVB-Htransmission signals via the UHF band, from about 470 MHz to about 890MHz, the 1670-1675 MHz band, and/or the L-band, from about 1400 MHz toabout 1700 MHz, for example. The RF receiver 153 a may enable receivingDVB-S2 transmission signals, for example. Moreover, the RF receiver 153a may enable receiving signals in cellular frequency bands, for example.Each frequency band supported by the RF receiver 153 a may have acorresponding front-end circuit for handling low noise amplification anddown conversion operations, for example. In this regard, the RF receiver153 a may be referred to as a multi-band receiver when it supports morethan one frequency band. In another embodiment of the invention, themobile terminal 150 may comprise more than one RF receiver 153 a,wherein each of the RF receiver 153 a may be a single-band or amulti-band receiver.

The RF receiver 153 a may quadrature down convert the received RF signalto a baseband frequency signal that comprises an in-phase (I) componentand a quadrature (Q) component. The RF receiver 153 a may perform directdown conversion of the received RF signal to a baseband frequencysignal, for example. In some instances, the RF receiver 153 a may enableanalog-to-digital conversion of the baseband signal components beforetransferring the components to the digital baseband processor 159. Inother instances, the RF receiver 153 a may transfer the baseband signalcomponents in analog form.

The digital baseband processor 159 may comprise suitable logic,circuitry, and/or code that may enable processing and/or handling ofbaseband frequency signals. In this regard, the digital basebandprocessor 159 may process or handle signals received from the RFreceiver 153 a and/or signals to be transferred to the RF transmitter153 b, when the RF transmitter 153 b is present, for transmission to thenetwork. The digital baseband processor 159 may also provide controland/or feedback information to the RF receiver 153 a and to the RFtransmitter 153 b based on information from the processed signals. Thedigital baseband processor 159 may communicate information and/or datafrom the processed signals to the processor 155 and/or to the memory157. Moreover, the digital baseband processor 159 may receiveinformation from the processor 155 and/or to the memory 157, which maybe processed and transferred to the RF transmitter 153 b fortransmission to the network.

The RF transmitter 153 b may comprise suitable logic, circuitry, and/orcode that may enable processing of RF signals for transmission. The RFtransmitter 153 b may enable transmission of RF signals in a pluralityof frequency bands. Moreover, the RF transmitter 153 b may enabletransmission of signals in cellular frequency bands, for example. Eachfrequency band supported by the RF transmitter 153 b may have acorresponding front-end circuit for handling amplification and upconversion operations, for example. In this regard, the RF transmitter153 b may be referred to as a multi-band transmitter when it supportsmore than one frequency band. In another embodiment of the invention,the mobile terminal 150 may comprise more than one RF transmitter 153 b,wherein each of the RF transmitter 153 b may be a single-band or amulti-band transmitter.

The RF transmitter 153 b may quadrature up convert the basebandfrequency signal comprising I/Q components to an RF signal. The RFtransmitter 153 b may perform direct up conversion of the basebandfrequency signal to a baseband frequency signal, for example. In someinstances, the RF transmitter 153 b may enable digital-to-analogconversion of the baseband signal components received from the digitalbaseband processor 159 before up conversion. In other instances, the RFtransmitter 153 b may receive baseband signal components in analog form.

The processor 155 may comprise suitable logic, circuitry, and/or codethat may enable control and/or data processing operations for the mobileterminal 150. The processor 155 may be utilized to control at least aportion of the RF receiver 153 a, the RF transmitter 153 b, the digitalbaseband processor 159, and/or the memory 157. In this regard, theprocessor 155 may generate at least one signal for controllingoperations within the mobile terminal 150. The processor 155 may alsoenable executing of applications that may be utilized by the mobileterminal 150. For example, the processor 155 may execute applicationsthat may enable displaying and/or interacting with content received viaDVB-H or DVB-S2 transmission signals in the mobile terminal 150.

The memory 157 may comprise suitable logic, circuitry, and/or code thatmay enable storage of data and/or other information utilized by themobile terminal 150. For example, the memory 157 may be utilized forstoring processed data generated by the digital baseband processor 159and/or the processor 155. The memory 157 may also be utilized to storeinformation, such as configuration information, that may be utilized tocontrol the operation of at least one block in the mobile terminal 150.For example, the memory 157 may comprise information necessary toconfigure the RF receiver 153 a to enable receiving DVB-H or DVB-S2transmission in the appropriate frequency band.

FIG. 1B is a block diagram illustrating exemplary communication betweena dual-band RF receiver and a digital baseband processor in a mobileterminal, in accordance with an embodiment of the invention. Referringto FIG. 1B, there is shown a dual-band RF receiver 160, ananalog-to-digital converter (ADC) 164, and a digital baseband processor162. The dual-band RF receiver 160 may comprise a UHF front-end 161 a,an L-band front-end 161 b, a baseband block 163 a, a received signalstrength indicator (RSSI) block 163 b, and a synthesizer 163 c. Thedual-band RF receiver 160, the analog-to-digital converter (ADC) 164,and/or the digital baseband processor 162 may be part of a mobileterminal, such as the mobile terminal 150 in FIG. 1A, for example.

The dual-band RF receiver 160 may comprise suitable logic, circuitry,and/or code that may enable handling of UHF and L-band signals. Thedual-band RF receiver 160 may be enabled via an enable signal, such asthe signal RxEN 169 a, for example. In this regard, enabling thedual-band RF receiver 160 via the signal RxEN 169 a by a 1:10 ON/OFFratio may allow time slicing in DVB-H while reducing power consumption.At least a portion of the circuitry within the dual-band RF receiver 160may be controlled via the control interface 169 b. The control interface169 b may receive information from, for example, a processor, such asthe processor 155 in FIG. 1A, or from the digital baseband processor162. The control interface 169 b may comprise more than one bit. Forexample, when implemented as a 2-bit interface, the control interface169 b may be an inter-integrated circuit (I2C) interface.

The UHF front-end 161 a may comprise suitable logic, circuitry, and/orcode that may enable low noise amplification and direct down conversionof UHF signals. In this regard, the UHF front-end 161 a may utilize anintegrated low noise amplifier (LNA) and mixers, such as passive mixers,for example. The UHF front-end 161 a may communicate the resultingbaseband frequency signals to the baseband block 133 a for furtherprocessing. U.S. application Ser. No. 11/385,081 filed on Mar. 21, 2006,provides a detailed description of a digital television environment, andis hereby incorporated by reference in its entirety.

The L-band front-end 161 b may comprise suitable logic, circuitry,and/or code that may enable low noise amplification and direct downconversion of L-band signals. In this regard, the L-band front-end 161 bmay utilize an integrated LNA and mixers, such as passive mixers, forexample. The L-band front-end 161 b may communicate the resultingbaseband frequency signals to the baseband block 163 a for furtherprocessing. The dual-band RF receiver 160 may enable one of the UHFfront-end 161 a and the L-band front-end 161 b based on currentcommunication conditions.

The synthesizer 163 c may comprise suitable logic, circuitry, and/orcode that may enable generating the appropriate local oscillator (LO)signal for performing direct down conversion in either the UHF front-end161 a or the L-band front-end 161 b. Since the synthesizer 163 c mayenable fractional division of a source frequency when generating the LOsignal, a large range of crystal oscillators may be utilized as afrequency source for the synthesizer 163 c. This approach may enable theuse of an existing crystal oscillator in a mobile terminal PCB, thusreducing the number of external components necessary to support theoperations of the dual-band RF receiver 160, for example. Thesynthesizer 163 may generate a common LO signal for the UHF front-end161 a and for the L-band front-end 161 b. In this regard, the UHFfront-end 161 a and the L-band front-end 161 b may enable dividing theLO signal in order to generate the appropriate signal to perform downconversion from the UHF band and from the L-band respectively. In someinstances, the synthesizer 163 may have at least one integrated voltagecontrolled oscillator (VCO) for generating the LO signal. In otherinstances, the VCO may be implemented outside the synthesizer 163.

The baseband block 163 a may comprise suitable logic, circuitry, and/orcode that may enable processing of I/Q components generated from thedirect down conversion operations in the UHF front-end 161 a and theL-band front-end 161 b. The baseband block 163 a may enableamplification and/or filtering of the I/Q components in analog form. Thebaseband block 163 a may communicate the processed I component, that is,signal 165 a, and the processed Q component, that is, signal 165 c, tothe ADC 164 for digital conversion.

The RSSI block 163 b may comprise suitable logic, circuitry, and/or codethat may enable measuring the strength, that is, the RSSI value, of areceived RF signal, whether UHF or L-band signal. The RSSI measurementmay be performed, for example, after the received RF signal is amplifiedin either the UHF front-end 161 a or the L-band front-end 161 b. TheRSSI block 163 b may communicate the analog RSSI measurement or signal165 e, to the ADC 164 for digital conversion.

The ADC 164 may comprise suitable logic, circuitry, and/or code that mayenable digital conversion of signals 165 a, 165 c, and/or 165 e tosignals 165 b, 165 d, and/or 165 f respectively. In some instances, theADC 164 may be integrated into the dual-band RF receiver 160 or into thedigital baseband processor 162.

The digital baseband processor 162 may comprise suitable logic,circuitry, and/or code that may enable processing and/or handling ofbaseband frequency signals. In this regard, the digital basebandprocessor 162 may be the same or substantially similar to the digitalbaseband processor 159 described in FIG. 1A. The digital basebandprocessor 162 may enable generating at least one signal, such as thesignals AGC_BB 167 a and AGC_RF 167 b, for adjusting the operations ofthe dual-band RF receiver 160. For example, the signal AGC_BB 167 a maybe utilized to adjust the gain provided by the baseband block 163 a onthe baseband frequency signals generated from either the UHF front-end161 a or the L-band front-end 161 b. In another example, the signalAGC_RF 167 b may be utilized to adjust the gain provided by anintegrated LNA in either the UHF front-end 161 a or the L-band front-end161 b. In another example, the digital baseband processor 162 maygenerate at least one control signal or control information communicatedto the dual-band RF receiver 160 via the control interface 169 b foradjusting operations within the dual-band RF receiver 160.

FIG. 1C is a block diagram of an exemplary satellite receiver, inaccordance with an embodiment of the invention. Referring to FIG. 1C,there is shown a digital satellite receiver system 100. The digitalsatellite receiver system 100 may comprise an antenna 102, a low noiseblock (LNB) 104, a direct conversion tuner 106, a digital receiver 108,and a backend decoder 110. The LNB 104 may comprise a mixer 114, and afrequency synthesizer 116. The direct conversion tuner 106 may comprisea mixer 118, a frequency synthesizer 120, a band pass filter (BPF) 122,and a low noise amplifier (LNA) 124. The digital receiver 108 maycomprise an analog to digital converter (ADC) 126, a mixer 128, a finiteimpulse response (FIR) filter 130, an equalizer 134, a decoder 136, aphysical frame acquisition block 138, and a direct digital frequencysynthesizer (DDFS) 140. The backend decoder 110 may comprise a transportdemultiplexer 142, and a MPEG/AVC decoder 144.

The LNB 104 may comprise suitable logic, circuitry and/or code that maybe enabled to receive a plurality of signals from a satellite, amplifythe received signals, and downconvert the received signals to a lowerfrequency band. The antenna 102 may be enabled to receive the pluralityof signals from one or more satellites. The mixer 114 may comprisesuitable logic, circuitry and/or code that may be enabled to downconvertthe received signals to a lower frequency band. The frequencysynthesizer 116 may comprise suitable logic, circuitry and/or code thatmay be enabled to generate a plurality of signals, for example, acompromise (C) band, Kurtz-under (Ku) band or Kurtz-above (Ka) bandsignals to be mixed with the received plurality of signals. The LNB 104may be enabled to downconvert a block of microwave frequencies asreceived from a satellite to a lower block range of frequencies in thecable to the digital receiver 108.

The mixer 118 may comprise suitable logic, circuitry and/or code thatmay be enabled to convert the received signals to a different frequencyband, for example, L band. The frequency synthesizer 120 may comprisesuitable logic, circuitry and/or code that may be enabled to generate aplurality of signals, for example, L band signals to be mixed with thereceived plurality of signals from the LNB 104. The band pass filter 122may comprise suitable logic, circuitry and/or code that may be enabledto filter the received signals and allow a plurality of received signalswithin a particular frequency band. The low noise amplifier 124 maycomprise suitable logic, circuitry, and/or code that may be enabled toreceive an input signal from the BPF 122 and amplify the received signalwith reduced additional noise.

The analog-to-digital converter (ND) 126 may comprise suitable logic,circuitry and/or code that may be enabled to convert the received analogsignal into a digital signal. The analog-to-digital converter 126 maygenerate a sampled digital representation of the filtered signal thatmay be communicated to the mixer 128 for processing. The mixer 128 maycomprise suitable logic, circuitry and/or code that may be enabled toconvert the received signals to a different frequency band.

The DDFS 140 may comprise suitable logic, circuitry and/or code that maybe enabled to vary an output signal frequency over a large range offrequencies, based on a single fixed-frequency precision referenceclock. The DDFS 140 may also be phase-tunable. The FIR filter 130 maycomprise suitable logic, circuitry and/or code that may be enabled tofilter the output signal generated from the mixer 128. The equalizer 134140 may comprise suitable logic, circuitry and/or code that may beenabled to reduce frequency distortion.

The decoder 136 may comprise suitable logic, circuitry and/or code thatmay be enabled to provide forward error correction for the receivedsignal. The decoder 136 may be enabled to utilize low density paritycheck (LDPC) codes to detect and correct any errors, which may occur inthe received signal. The decoder 136 may comprise an outerBose-Chaudhuri-Hocquenghem (BCH) decoder coupled with a LDPC innerdecoder. The BCH decoder may be utilized to reduce the effects of anerror floor. In accordance with an embodiment of the invention, the BCHdecoder may be eliminated by utilizing a improved code design with ashorter frame size, for example, 43200 bits, which may reduce decoderlatency.

The modulation mode and code rate of the digital receiver 108 may bevaried from frame to frame in the physical layer of the DVB-S2 signal.The frames may be assigned to different transport streams. The QPSKmodulation scheme may provide two bits per symbol, for example, whilethe 8PSK modulation scheme may provide three bits per symbol, forexample. As a result, the 8PSK modulation scheme may enable the digitalreceiver 108 to carry about 50 percent more information within the samebandwidth than the QPSK modulation scheme, but may also require highercarrier to noise ratio for reception. The 8PSK modulation scheme may beutilized for broadcasting applications for high-power satellites withlow noise figures.

The physical frame acquisition block 138 may comprise suitable logic,circuitry and/or code that may be enabled to add pilots to the receivedsignal to facilitate signal recovery. The physical frame of the receivedDVB-S2 signal may comprise a header and a payload. The header mayinclude synchronization information related to signaling. The digitalreceiver 108 may be enabled to utilize adaptive coding and modulation(ACM) to optimize point-to-point applications. In the ACM mode, thedigital receiver 108 may be communicatively coupled to a transmitter viaan uplink. The return path may provide an update of the signal to noiseratio (SNR) at the receive site available at the uplink station in orderto modify coding and modulation to optimize the bit rate throughput.

The transport demultiplexer 142 may comprise suitable logic, circuitryand/or code that may be enabled to demultiplex the received decodedsignals from the digital receiver 108. The MPEG/AVC decoder 144 maycomprise suitable logic, circuitry and/or code that may be enabled todecode the received signals into an audio signal and a video signal.

FIG. 2A is a diagram that illustrates an exemplary QPSK modulated framestructure without pilots that may be utilized in connection with anembodiment of the invention. Referring to FIG. 2A, there is shown aframe 202 that may be QPSK modulated without a pilot. The frame 202 maybe for example, a DVB-S2 frame or a DVB-H frame. The frame 202 maycomprise 32490 symbols, for example. The frame 202 may comprise a header204. The header 204 may comprise synchronization information related tosignaling.

FIG. 2B is a diagram that illustrates an exemplary 8PSK modulated framestructure without pilots that may be utilized in connection with anembodiment of the invention. Referring to FIG. 2B, there is shown aframe 252 that may be 8PSK modulated without a pilot. The frame 252 maybe for example, a DVB-S2 frame or a DVB-H frame. The frame 252 maycomprise 21690 symbols, for example. The frame 252 may comprise a header254. The header 254 may comprise synchronization information related tosignaling.

FIG. 3A is a diagram that illustrates an exemplary QPSK modulated framestructure with pilots that may be utilized in connection with anembodiment of the invention. Referring to FIG. 3A, there is shown aframe 302 that may be QPSK modulated with pilots. The frame 302 may befor example, a DVB-S2 frame or a DVB-H frame. The frame 302 may comprise33282 symbols, for example. The frame 302 may comprise a header 304, anda plurality of pilots, for example, 308 and payload information betweeneach of the plurality of pilots, for example, 306. The frame 302 maycomprise 22 pilots, for example, and each pilot may be 36 symbols wide,for example. The frame 302 may comprise 792 pilot symbols, for example.

FIG. 3B is a diagram that illustrates an exemplary 8PSK modulated framestructure with pilots that may be utilized in connection with anembodiment of the invention. Referring to FIG. 3B, there is shown aframe 302 that may be 8PSK modulated with pilots. The frame 352 may befor example, a DVB-S2 frame or a DVB-H frame. The frame 352 may comprise22194 symbols, for example. The frame 352 may comprise a header 354, anda plurality of pilots, for example, 358 and payload information betweeneach of the plurality of pilots, for example, 356. The frame 352 maycomprise 14 pilots, for example, and each pilot may be 36 symbols wide,for example. The frame 352 may comprise 504 pilot symbols, for example.

FIG. 4A is a diagram that illustrates an exemplary 8PSK modulated framestructure with pilots that may be utilized in connection with anembodiment of the invention. Referring to FIG. 4A, there is shown aframe 402 that may be 8PSK modulated with pilots. The frame 402 may befor example, a DVB-S2 frame or a DVB-H frame. The frame 402 may comprise22194 symbols at a 20 Mbaud symbol rate, for example. The frame 402 maycomprise a header 404, and a plurality of pilots, for example, 408 andpayload information between each of the plurality of pilots, forexample, 406. The frame 402 may comprise 14 pilots, for example, andeach pilot may be 36 symbols wide, for example. The frame 402 maycomprise 504 pilot symbols, for example. The header 404 may be 90symbols wide, for example.

FIG. 4B is a diagram that illustrates an exemplary 8PSK modulated framestructure with variable pilots, in accordance with an embodiment of theinvention. Referring to FIG. 4B, there is shown a frame 452 that may be8PSK modulated with pilots. The frame 452 may be for example, a DVB-S2frame or a DVB-H frame. The frame 452 may comprise 22194 symbols at a 10Mbaud symbol rate, for example. The frame 452 may comprise a header 454,and a plurality of pilots, for example, 458, 459, and spacing betweeneach of the plurality of pilots, for example, 456. The digital receiver108 may be configured to handle dynamically varying of spacing betweenone or more pilots within at least one frame based on a determinedsymbol rate. The digital receiver 108 may process pilots with variablesize based on the determined symbol rate. For example, the frame 452 maycomprise 28 pilots, for example, and each pilot may be 18 symbols wide,for example. The frame 452 may comprise 504 pilot symbols, for example.The header 454 may be 90 symbols wide, for example.

FIG. 5 is a diagram that illustrates an exemplary frame structure forsupporting mobile satellite video reception, in accordance with anembodiment of the invention. Referring to FIG. 5, there is shown areceived packet stream 500. The packet stream 500 may comprise aplurality of frames, for example, frame 1 502. The frame 1 502 maycomprise a header 504 and a payload 506. The received packet stream 500may be for example, a DVB-S2 packet stream or a DVB-H packet stream. Thepacket stream 500 may comprise a plurality of programs, for example,program #1 . . . program #N. The digital receiver 108 may be enabled todetermining a size of each of the plurality of received programs. Thedigital receiver 108 may be enabled to dynamically vary spacing betweenone or more pilots based on the determined size of each of the pluralityof received programs. The spacing between the pilots may be varied toaccommodate a whole program, for example, program #1 within a frame, forexample, frame 1 502. The digital receiver 108 may be switched ON basedon receiving at least one selected program among the plurality ofreceived programs. The digital receiver 108 may be enabled to save powerby switching ON during the duration of the received frame comprising theselected program. For example, the digital receiver 108 may be switchedON for the duration of frame 1 502, which comprises the selectedprogram, program #1.

FIG. 6 is a flowchart illustrating exemplary steps for satellitecommunication, in accordance with an embodiment of the invention.Referring to FIG. 6, exemplary steps may begin at step 602. In step 604,the digital receiver 108 may be enabled to determine a symbol rate ofthe received frames. In step 606, the digital receiver 108 may beenabled to determine a size of each of the received programs. In step608, the digital receiver 108 may be enabled to dynamically varyspacing, for example, 456 between one or more pilots, for example,between pilot 458 and pilot 459 within at least one frame 452 based onthe determined size of each of the plurality of received programs, forexample, program #1. In step 610, the digital receiver 108 may beenabled to dynamically vary spacing, for example, 456 between one ormore pilots, for example, between pilot 458 and pilot 459 within atleast one frame 452 based on the determined symbol rate, for example, 10Mbaud. The digital receiver 108 may be enabled to dynamically vary asize of one or more pilots, for example, 458 based on the determinedsymbol rate. In step 612, the digital receiver 108 may be enabled tomodulate each frame, for example, frame 452 using one of: a quadraturephase shift keying (QPSK), a 8-phase shift keying (8PSK), a 16-phaseasymmetric phase shift keying (16APSK), and a 32-phase asymmetric phaseshift keying (32APSK) modulation scheme. In step 614, the digitalreceiver 108 may be switched ON based on receiving at least one selectedprogram among the plurality of received programs. The digital receiver108 may be enabled to save power by switching ON during the duration ofthe received frame comprising the selected program. For example, thedigital receiver 108 may be switched ON for the duration of frame 1 502,which comprises the selected program, program #1. Control the passes toend step 616.

In accordance with an embodiment of the invention, a method and systemfor satellite communication may include a digital receiver 108 handlingdigital video broadcasting. The digital receiver 108 may be enabled todynamically vary spacing, for example, 456 between one or more pilots,for example, between pilot 458 and pilot 459 within at least one frame452 based on a determined symbol rate, for example, 10 Mbaud. Thedigital receiver 108 may be enabled to determining a size of each of theplurality of received programs. The digital receiver 108 may be enabledto dynamically vary spacing, for example, 456 between one or morepilots, for example, 458 and 459 based on the determined size of each ofthe plurality of received programs, for example, program #1. The digitalreceiver 108 may be switched ON based on receiving at least one selectedprogram among the plurality of received programs. The digital receiver108 may be enabled to save power by switching ON during the duration ofthe received frame comprising the selected program. For example, thedigital receiver 108 may be switched ON for the duration of frame 1 502,which comprises the selected program, program #1.

The digital receiver 108 may be enabled to dynamically vary a size ofone or more pilots, for example, 458 based on the determined symbolrate. The digital receiver 108 may be enabled to modulate each frame,for example, frame 452 using one of: a quadrature phase shift keying(QPSK), a 8-phase shift keying (8PSK), a 16-phase asymmetric phase shiftkeying (16APSK), and a 32-phase asymmetric phase shift keying (32APSK)modulation scheme. The digital receiver 108 may be enabled to handledigital video broadcasting comprising a DVB-S2 standard and a DVB-Hstandard.

Another embodiment of the invention may provide a machine-readablestorage, having stored thereon, a computer program having at least onecode section executable by a machine, thereby causing the machine toperform the steps as described above for satellite communication.

Accordingly, the present invention may be realized in hardware,software, or a combination of hardware and software. The presentinvention may be realized in a centralized fashion in at least onecomputer system, or in a distributed fashion where different elementsare spread across several interconnected computer systems. Any kind ofcomputer system or other apparatus adapted for carrying out the methodsdescribed herein is suited. A typical combination of hardware andsoftware may be a general-purpose computer system with a computerprogram that, when being loaded and executed, controls the computersystem such that it carries out the methods described herein.

The present invention may also be embedded in a computer programproduct, which comprises all the features enabling the implementation ofthe methods described herein, and which when loaded in a computer systemis able to carry out these methods. Computer program in the presentcontext means any expression, in any language, code or notation, of aset of instructions intended to cause a system having an informationprocessing capability to perform a particular function either directlyor after either or both of the following: a) conversion to anotherlanguage, code or notation; b) reproduction in a different materialform.

While the present invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the present invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the present invention without departing from its scope.Therefore, it is intended that the present invention not be limited tothe particular embodiment disclosed, but that the present invention willinclude all embodiments falling within the scope of the appended claims.

Therefore, at least the following is claimed:
 1. A system, comprising:first circuitry of a receiver configured to determine a symbol rate of areceived communication signal; and second circuitry of the receiverconfigured to determine a location of one or more pilots within thereceived communication signal based at least in part on the symbol rate,wherein determining the location of the one or more pilots enablessupport for one or more payload sizes; wherein the receivedcommunication signal employs orthogonal frequency division multiplexing(OFDM).
 2. The system of claim 1, wherein the second circuitry isfurther configured to determine the location of the one or more pilotswithin a frame of the received communication signal based at least inpart on the symbol rate.
 3. The system of claim 1, wherein the secondcircuitry is further configured to determine a size of the one or morepilots within the received communication signal based at least in parton the symbol rate.
 4. The system of claim 1, wherein the receiver isconfigured to receive signals in a cellular frequency band.
 5. Thesystem of claim 1, wherein the location of the one or more pilots isdynamically determined.
 6. The system of claim 1, further comprising amobile terminal, wherein the receiver is integrated in the mobileterminal.
 7. The system of claim 6, wherein the mobile terminal furthercomprises a transmitter.
 8. A system, comprising: first circuitry of areceiver configured to determine a symbol rate of a receivedcommunication signal; and second circuitry of the receiver configured todynamically determine a spacing between two or more pilots within thereceived communication signal based at least in part on the symbol rate,wherein determining the spacing between the two or more pilots enablessupport for one or more payload sizes, wherein the receivedcommunication signal employs orthogonal frequency division multiplexing(OFDM).
 9. The system of claim 8, wherein the second circuitry isfurther configured to determine the spacing between the two or morepilots within a frame of the received communication signal based atleast in part on the symbol rate.
 10. The system of claim 8, wherein thespacing of the two or more pilots is dynamically determined.
 11. Thesystem of claim 8, wherein the second circuitry is further configured todetermine a size of one or more pilots within the received communicationsignal based at least in part on the symbol rate.
 12. A method,comprising: receiving, in a wireless communication device, acommunication signal; determining, in the wireless communication device,a symbol rate of the communication signal; and determining, in thewireless communication device, a location of one or more pilots in thecommunication signal based at least in part on the symbol rate, whereindetermining the location of the one or more pilots enables support forone or more payload sizes, wherein the communication signal employsorthogonal frequency division multiplexing (OFDM).
 13. The method ofclaim 12, further comprising recovering, in the wireless communicationdevice, data from the communication signal based at least in part on thelocation of the one or more pilots.
 14. The method of claim 12, whereinthe communication signal is a cellular network signal.
 15. The method ofclaim 12, wherein the wireless communication device comprises a mobileterminal.
 16. The method of claim 12, further comprising determining, inthe wireless communication device, a spacing between two or more pilotswithin the communication signal based at least in part on the symbolrate.
 17. The method of claim 12, further comprising determining, in thewireless communication device, a size of the one more pilots within thecommunication signal based at least in part on the symbol rate.